The improvement of the present application relates to an improved method and means for permitting a central processing unit (CPU) of a data processing system to interact with apparatus which is alien to the operating system under which the data processing system is operating. That is, the operating system has no configuration data concerning the alien apparatus in its start up configuration tables; yet the improvement permits the CPU to control the apparatus and/or transfer data and commands with the apparatus.
Prior Art Data processing systems include a system configuration which specifies the devices and programs that form a particular processing system. The configuration file contains commands that the operating system executes as part of the procedure for starting up a system.
Data processing systems typically include start up code which initializes all configured devices. The procedure includes reading tables that specify configurations of boards, disks and other devices connected to the system. If a device is not so configured, it typically cannot be coupled to for data transfer with the processor of the system because the operating system is unable to control the data transfer, i.e., the device is "alien" to the operating system. O. S. would reject transfers and remove spurious device signal sources.